According to their various utilizations, variable transmissions are developed for several gear ratios, for instance in a so-called hill-climbing speed type, wherein the highest speed has a gear ratio of 1.0, and, if chosen, also in a high-speed construction type with an overdrive and a gear ratio for instance of 0.79, for the highest speed. In order to build such variants, the gear-shift devices have to be adjusted. In the one case, for a direct transmission to the gearing at a gear ratio of 1, the clutch sleeve has to be shifted in direction toward the left, while in the other case it has to be shifted in the opposite direction. The shifting diagram for the driver, however, has to remain unchanged, and for this purpose, a reversal in the gear-shift device becomes necessary in the transmission.
It is known to support the shift rocking arm in question not like the other shift rocking arms, which are pivoted between the slide crank and the engagement point in the shift rail, within the housing, so that when actuated, a reversal in the direction of the clutch sleeve results, but to provide for the support of the shift rocking arm at one end thereof and to arrange the slide crank between the engagement point in the shift rail and this support point. As a result, in spite of the reversal in the clutch sleeve, with respect to the other clutch sleeves the shift direction for the driver, at the manual shift lever, stays the same. But it is not always possible to put into practice this relatively simple modification, because this way the required shift path for the clutch sleeve can not be achieved unless the support point for the shift rocking arm is located outside the transmission housing because of the length of the rocker arm.
Therefore, it is already known to use this type of a shift rocker arm and additionally to increase the shift path in the area of the shift rails.
In addition to two new swing bolts and a new considerably bigger shift rocking arm, the arrangements in the area of the shift rail are quite complicated in construction and assembly.